mercer



' Patented Apr. 4, I899. J. R.- MERCER. AUTOMATIC VEHICLE BRAKE. (Application filed Aug. 21, 1897. Renewed'Sept. 10, 1898.)

(No Model.)

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NITED STATES PATENT OFFICE.

JOSEPH R. MERCER, OF HARTFORD, MISSOURI, ASSIGNOR OF ONE-HALF TO JOHN W. MARTIN, OF SAME PLACE.

AUTOMATIC VEHICLE-BRAKE.

SPECIFICATION forming part of Letters Patent No. 622,378, dated April 4:, 1899.

Application filed August 21, 1897. Renewed September 10, 1898. Serial No. 690,688. (No model.)

T0 on whom it nuty concern.-

Be it known that I, JOSEPH R. MERCER, a citizen of the United States, residing at Hartford, in the county of Putnam and State of Missouri, have invented certain new and useful Improvements in Automatic Brakes for Vehicles; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form'a part of this specification.

This invention relates to improvements in that class of vehicle-brakes which are designed to be automatically set to check the momentum of the vehicle while stopping and in descending grades; and the invention has for its objects, first, the provision of a simply-constructed and efficient brake of this character which is susceptible of being applied to a vehicle without the necessity of modifying its construction, and, second, the construction of a brake-shoe which will onable the vehicle to be moved rearwardly or backed without hindrance.

The invention consists-in the details of construction and operation set forth in the following description, which is to be read in connection with the accompanying drawings, in which- Figure 1 is a plan View of a vehicle with my improved brake applied thereto. Fig. 2 is a sectional view of the same, the idle and set positions of the brake parts-being shown, respectively, in full and dotted lines. Fig. 3 is a detail view, enlarged, of one of the brakeshoes, the dotted lines indicating the position the shoe assumes when the vehicle is being backed.

Referring to the said drawings by letter, A denotes the rear axle of a vehicle; I) b, the rear wheels; O, the front axle; d, the front wheels, and e is a frame connecting the axles, these parts being of ordinary construction. The tongue f of the vehicle is pivotally connected through a rod g with forwardly-projecting arms 9 g, forming extensions of the fifth-wheel. The construction of the tongue f will hereinafter appear.

The brake-shoes H H are adapted to engage the peripheries of the rear wheels 1) forward of said wheels and are pivotally secured to a brake-beam 2',which is connected to swing forward and backward below the frame 6 by rods jj, held to turn in eyes or bearings 9'' on a supporting-bar e on the said frame, the rod being bent downward beyond the bar ends and its ends terminating in hooks 7 which engage eyes or staples e" on the brake-beam 1 Depending from the frame forward of the rear axle are'bearings 7c, in which is mounted a rock shaft is, carrying arms 10 Z0 the upper arms being connected with the brake-beam by rods 15 while the lower arm k is connected by a rod k to the lower arm Z of a rock-lever Z, pivotally mounted on the rear end of the tongue f, said arm Z having a number of perforations to receive adjust-ably the end of the rod 10 for varying the throw ofthe rock-shaft and the movement of the brakebea-m, as will be understood. The lever Zbe- -tween its ends .is open to receive a rear central extension f of the tongue f and is pivoted on the rod g. The upper arm Z of this rock-lever is connected by a rod m with the pivot pin or bolt 17. of the doubletree n, which latter is mounted to have a forward and a rearward movement, the lower end 01. of

the bolt n being slidably arranged in a bracket f on the tongue, which bracket is slotted to receive the said bolt. The upper arm Z of the lever Z is also connected with the neckyokeo at the forward end of the tongue f by a rod 19, having flexible ends which are passed over sheaves f f mounted in the front and rear ends, respectively, of the tongue f and its extension f.

The brake-shoes are of peculiar construction, the braking-face of the shoe proper which contacts with the wheel-tread being substantially straight from the upper end to the point designated at w, and beyond said point the face is rounded off for apurpose to be presently explained. The shoes are confined in frames h, and connection between the frames and brake-beam is made by means of arms 71. h, which'are pivotally secured at one end to the shoe and at the other end pivotally to eyes '5 on the beam.

11 are stops which limit the movement of the shoes.

The operation is as follows: With the neckyoke and doubletree in their forward positions, as shown in full lines in Fig. 2, the brakes are idle; but the rearward movement of said neck-yoke causes the brake-shoes, through the connections described, to contact with the peripheries of the rear wheels and prevent their turning, with the effect of slowing or stopping the progress of the vehicle. In descending grades the movement of the horse or other animal is checked, and the forward inclination of the vehicle causes the neck-yoke and doubletree to slide backward, with the result stated. A similar operation also results in the action of stopping the animal by drawing in the reins. The brakes are released by the pulling action on the doubletree, which has the effect, through the rod 1%, of moving the lever Z, and thereby releasing the tension on the brakes. In backing the vehicle the rear wheels are oppositely revolved, and although in this case the brakeshoes are forced against the wheels the stated revolution of the latter causes the shoes to rise and present the rounded surface to the wheel-tread, and thereby to diminish the friction. The purpose of the stops 2' is to limit the upward movement of the shoes, and the weight of said shoes operates to return them to their normal position as soon as they are free from contact with the wheel.

As previously stated, my invention is of simple construction and may be readily applied with little expense to existing vehicles. The efliciency of the invention is the maximum, as the tension of the brake is governed by the degree of inclination of the ground and by the drawing action of the reins.

The peculiar shape of brake-shoe employed enables the vehicle to be backed without interference and without the employment of separate devices to render the brake idle during this operation.

I claim as my invention-- 1. The combination with a wheeled vehicle and its tongue, of a brake consisting of brakeshoes pivotally connected to a swing-beam, a

rock-shaft carrying arms at its upper and lower side, the upper arms having rod connection with said beam, a rock-lever pivoted at the rear end of the tongue having rod connection at its lower end with the lower arm of the rock-shaft, a doubletree slidably mounted and connected with the upper arm of the rocklever, a neck-yoke and a connection between said neck-yoke and the upper arm, substantially as set forth.

2. The combination with a wheeled vehicle and its tongue, of a brake consisting of brakeshoes pivotally connected to a swing-beam, a rock-shaft carrying arms at its upper and lower side, the upper arms having rod connection with said beam, a rock-lever pivoted on a rear extension of the tongue, a rod connecting the lower arm of said lever with the lower arm on the rock-shaft, a slidable doubletree mounted on a slotted bracket in the tongue and having rod connection with the upper arm of the lover, a neck-yoke and a connection between said neck-yoke and the upper arm of the lever passed over sheaves mounted in the ends of the tongue, substantially as described.

3. The combination with a wheeled vehicle and its tongue, of a brake consisting of brakeshoes each of which is pivotally connected with a swing-beam and having a portion of its face straight and the remaining lower portion rounded, stops on the beam at said brakeshoes, a rock-shaft carrying arms having rod connection with said beam, a rock-lever pivoted at the rear end of the tongue having rod connection with the rock-shaft, a doubletree slidably mounted and connected with the upper arm of the rock-lever, a neck-yoke and a connection between said neck-yoke and rocklever, substantially as set forth.

In testimony whereof I afiix my signature in presence of two witnesses. Y

J OSEPII R. MERCER.

\Vitnesses:

E. V. W ARNICK, A. B. BARNHoUsE. 

